The invention concerns a method and a device for insertion of digital data having a first bit rate into a stream of digital data having a second bit rate greater than the first. The invention is can be used notably for the insertion of Teletext data in a digitized video signal.
Classically, during an "analog" transmission, Teletext data are inserted in the composite analog video signal in the lines of the vertical blanking interval.
In image compression systems, the data corresponding to the image and supplementary data such as Teletext data can be transmitted in different packets. Since some receivers incorporate Teletext decoders, to avoid redundancy in the Teletext function in the compressed signal decoder, an analog video signal containing the Teletext data is fed to the receiver.
The bit rate of the Teletext data is 6.9375 Mbit/s, whereas the frequency of a video source complying with the CCIR 601 digital standard Is 13.5 MHz for the luminance.